Method and apparatus for producing structural metal bars of various different commercial shapes and lengths



March 23, 1965 E H SIGAL 3,174,316

METHOD AND APPARATUS FDR PRO DUCING STRUCTURAL METAL BARS OF VARIOUS DIFFERENT COMMERCIAL SHAPES AND LENGTHS Filed April 3, 1962 2 Sheets-Sheet 1 33v 1 l 6 *T i, )6. ,7 a I 34 I v L0 L 44.,- 29' f Lm'nim. {I L s I 0T Lmi ILIM'I/ q L 4/ 42 I! '52 45 {HA T) I 45 E. H. SIGAL 3,174,316

2 Sheets-Sheet 2 VARIOUS DIFFERENT COMMERCIAL SHAPES AND LENGTHS METHOD AND APPARATUS FOR PRODUCING STRUCTURAL METAL BARS OF March 23, 1965 Filed April :5, 1962 w m m Q 1 1w 0 w i I I N a A q 5 I. m i RR R fi r0 P lHH |;|-IlIH| w M l, L I a 7 3 Id 5 l 6 L P4 3 .M M II I I I l 0 6 L 0 we a A M firw rwu MTL L 1.77 I l 1 I l l v C 6 v v A. M a n a 5 v. a M M w A w. d L M fi a 7 l I. 5 l V 1/ I III III. l I I I .ll 5 7 n P 4 A u 0 L at 5 r 6 II III I I I I 4 8 .Il llllll v 5 I 1|i|| II III .3 w

United States Patent 3 174 316 METHOD AND APPARATUS EGR PRODUCING STRUCTURAL NETAL BARS 0F VARiGUd DE- FERENT COMIv IERCIAL SHAPES AND LENGTHS Everard Henri Sigal, St. ingbert, Saar, Germany, assignor to Verwaltungsgesellschatt Mueller and Neumann Gifene Handelsgesellschaft, St. l nghert, am, Germany Filed Apr. 3, 1962, Ser. No. 184,806 11 Eiaims. (Cl. 72--8) This invention relates generally to a method and apparatus for producing structural metal bars of various different commercial shapes and lengths. More specifically the invention relates to a method and apparatus for subdividing an elongated bar, being rolled from a single billet, into a predetermined number of individual bars of substantially equal commercial length. Although the invention is specifically shown and described herein in connection with the production of finished commercial structural bars it is equally well adapted and used for subdividing larger metal billets into smaller billets which are subsequently rolled into commercial bars.

In the production of finished structural bars, as well as semi-finished members, such as billets, an elongated bar of the desired cross sectional shape, is rolled from a single billet and then cut into a plurality of individual sections of equal length by means of a shear which is adjustable to various different length of cuts. This means Waste, since the starting material is never uniform. The subdividing of finished stock into sections of equal commercial lengths is essential, whereas semi-finished goods, eg. billets, are subdivided into equal length sections in order to avoid during further rolling any differences in the lengths of the finished bars. But particularly in the subdividing of billets into constantly equal lengths the waste which is necessarily incurred, may be very substantial.

Assuming that in the subdivision of rolled stock the waste would be equal to zero if each rolled bar were subdivided into exactly equal sections, it would :be conceivable to measure the length of rolled-out bars and accordingly, with a given number of individual bars, to determine the equal lengths of cuts. However, in the case of a continuous mill train, where the front end of a bar is already in the shear while the other end of the bar is still engaged in the rolling process, it is not feasible to measure the total length of the rolled bar because the shear is positioned too closely behind the last roll stand.

Of course, in the solution of the problem of subdividing without waste a total length of rolled stock, which varies from bar to bar, it would be useless to expect that only individual rods of equal lengths would be obtained. This must be recognized and accepted, under the assumption, however, that in spite of subdivision without Waste all individual bars are kept within a predetermined length tolerance AL=L L If this tolerance is not too great, it is quite feasible, for example, to roll in a semifinishing mill train billets of not exactly equal lengths and to feed these billets to a finishing roll train, because the savings in heat and output with the waste-free subdividing in the semi-finishing train outweigh the cutting waste in the subsequent finishing train.

One of the principal objects of the invention is to provide a method for the subdivision of finished rolled stock, and of billets, which, keeping in mind the varying total lengths of rolled bars because of variations in the initial material, makes possible a subdivision of the rolled bar without cutting waste even if, in the course of continuous rolling, the rolled bar can at no place be measured to a desired total length so promptly that the "ice separating device can still be regulated at a variable rate. Assuming the existence of a device for the separating of rolled stock, e.g. a shear or saw, which can be adjusted for variable cutting lengths, a method is proposed according to the invention, in which each starting cross section of a billet is weighed before being inserted into a continuous mill train, next there is determined from the starting weight G the total length L corresponding to the final cross section Q, and from this total length L is calculated the length of an individual section which is determined on the basis of the estimated number p of the individual sections.

Another object of the invention is to maintain a predetermined length tolerance AL=L L for the individual bars by changing the number of the individual sections if the predetermined length tolerance is exceeded.

The teaching disclosed above results in the waste-free subdividing of a total bar length calculated in advance into exactly equal individual lengths if the calculated total length corresponds exactly to the actual total length. But if, because of inaccuracies in the weighing operation or in the adjustment of the specific weight, orbecause of production losses difiicult to estimate or of differences between the pro-adjusted finished cross-section and the actual rolled finished cross section, the effective total length L is different, then there is left over a remainder piece of undetermined length.

It is a further object of the invention, even though the total bar length may deviate from the calculated value, that remainder pieces of a certain minimum length R will be obtained which are still long enough for further processing even if they lie below the lower tolerance value L applicable to the other individual bars.

According to the invention, the determined theoretical total bar length L is falsified by the addition of a tolerance allowance AL which is the same as, or smaller than, the difference betwen the minimum individual bar length L and a remainder length R admissible for the last bar. Thus, it is not the theoretical total length L, derived from the weighing operation but the sum L plus AL which is fictitiously subdivided into equal individual lengths. If the effective total length corresponds to that sum, then the division into equal individual lengths takes place without a remainder piece. In the other marginal case, if the eifective total length is equal to the theoretical total length, then there is missing on the last bar at most the tolerance addition AL which, however, according to the assumption postulated, is the same as, or smaller than, L R Therefore, the last bar is the same as, or larger than, the still admissible value R for the remainder bar.

As described so far, deviations in the determined total length L are taken care of by magnifying by AL,,. But it is also possible that minus-deviations may occur. This is more likely because, the wear of the rolls leads no larger finished cross sections than the adjustment provides for, whereby, at the given initial weight, the effective total length will be smaller.

Research into the weighing. accuracy of modern electronic scales and other technical efiects of the rolling process upon the actual total length as well as into the requirements of rolling mills concerning the minimum length of a last bar has brought out that the difference between the desired regular lengths L to L and the remainer length R is greater, percentage-wise, than the percentage difference between the theoretical and the effective total length. While :l% might be adequate in relation to the total length, a final remainder bar of 8 m. is, for example, still acceptable with a regular length of a median 10 m. for the individual bar. Thus, a final bar may fall below the regular length by as much as 20% The invention further provides a Way for largely eliminating the factors of uncertainty in the determination of the effective total length, so as to be able to keep the tolerance'small and the remainder piece large. The greatest factor of uncertainty would seem to be the effective size of the finished cross section Qeff- According to the invention, there is provided beyond the last roll stand a measuring device for determining the effective finished cross section, whose measured value replaces the pre-adjusted value Q. Even if the rotating shear is stationed shortly beyond the last roll stand, an electronic calculating apparatus works so fast that the already made calculation with the pre-adjusted cross section value can still be repeated with a new, more correct value for the total length and the cutting time sequence can still be corrected before the first order reaches the shear. The still remaininginfiuences from the weighing tolerance, the production losses etc. are then encompassed with certainty by the adjusted plus-tolerance, i.e. there will rather regularly result a remainder bar of R because the effective and the theoretical total lengths are now almost identical.

Similarly, the feed speed of the rolled stock can be measured on the rolled stock itself rather than on the last roll stand, in order to determine the advance and the wear of the rolls. Also the speed factor could be currentlyintroduced into the calculations.

Still another object of the invention is the provision of aneflicient, and relatively simple apparatus, for carrying out the herein described method of the invention.

Having stated the principal objects of the'invention other and more specific objects thereof will be apparent from the following specification and the accompanying drawings forming a part thereof wherein:

FIGURE 1 is a schematic presentation of a continuous rolling mill train with a rotating shear for subdividing the rolled bar into respectively equal individual lengths;

FIGURE '2 shows in principle the control circuit for a calculating device for determining the respective section lengths with consideration given to a rare-determined tolerance, and for controlling the operation of the shear;

FIGURE 3 shows schematically the various lengths and their interrelationships in the subdividing of the remainder piece, and

FIGURE 4 shows in principle the control circuit of a calculator apparatusfor carrying out the method according to FlGURE 3.

In FIGURE 1, a scale serves to determine the initial Weight of a billet 26'. .The billet is rolled in a continuous rolling mill train 27 into. an elongated bar B, having a finished cross section Q, which is to be subdivided into individual bars 26 in such a manner that no cutting waste developsand that the individual lengths of the bars 26 lie withinapredetermined tolerance of L to L For the subdividing of the rolled bar there is provided a rotating. shear.28 forcutting the elongated moving rolled bar, which could also be replaced by a flying shear or the like. A photocell 29 gives the signal for switching in the rotating shear 28. T achodynamos 30 and 31 are provided at the last roll stand. as well as at the shear, on the one hand for the purpose of. determining the rotational speed of the rolls and on the other hand in order to bring about asynchronization of the shear .with the last roll stand in a known manner.

The initial weight G of the billet 26 is fed into the electronic calculating apparatus according to FIGURE 2 at 32. At the first'computing station 33, the product is formulated from the weight G and thepre-adjustable, reciprocal value of the weight per unit of length, with Q being the finished cross section of the rolled-out bar and y the specific weight of the billet. The reciprocal value is.forrnulated at the station 34, with the individual were values Q and 7 b ing selectively pre-adjustable by means of the devices 35 and 36 which are manually adjustable. The result from the computing station 33 is the total bar len th L which is then fed to a second computing station 37.

At this second computing station 37, the cutting length L is determined by means of a division of the total length L by the number p of the individual sections which can be pre-selected at the station 33. It should be noted that the total length L is, however, merely an imagined magnitude, since it does not appear in connection with continuous rolling and the placement of the shear 28 closely behind the mill train.

in order to determine whether the cutting length L computed in 37', which is fed to station lies within the pro-established tolerance of L to L the calculated cutting length L is compared at a third computing station 40 with the pre-adjustable extreme values L and L with an impulse for changing the number p of the individual sections being given out by this station as long as the calculated cutting length L lies outside the adjusted extreme values.

The extreme values are pro-adjustable at the adjusting devices 41 and 42. When the comparison with the calculated cutting length L at the computing station 3% indicates that the condition L L L is fulfilled, a return signal goes to station via conductor 43. But if the computed cutting length L lies outside the predetermined tolerance, an impulse for changing the cutting number p goes from the computing station 4% via the conductor 44 to the stat-ion 35. This impulse is being given for the purpose and for such a length of time until the change of p in the course of repeated computing operations leads to a bar length L which satisfies the condition mentioned. The number p is reduced if the computed cutting length lies below L and is increased if the cutting length lies above L In general, a change in the bar number p by only about 1 would be in question, since the starting material normally does not exhibit such great dilterences in weight that a greater change in the bar number from the previously calculated ideal bar number could be expected. A

It must be noted that the measure for maintaining the length tolerance or the individual sections by changing the number of individual sections cannot always be carried out independently of the zone of tolerance. The relationship holds for the minimum adjustable zone of tolerance, is. the product of zone tolerance and number of bars must amount to at least the lower tolerance limit for the individual sections. In practice, particularly in the subdividing of billets which do not have to have specified commercial lengths with a narrow tolerance because they are to be further processed in the same rolling mill, the tolerance zone, which is generally obtained by measuring the furnace, and the number of bars are rarely so small that their product is smaller than the minimum length for the individual sections.

The computing operations must have run their course through the forward end of the bar in the time between the weighing operation and the signaling by the photo cell 29 which is disposed in the roll train beyond the last finish roll stand. The computing operations are initiated by the initial weight G. As the forward end of the bar passes the photo cell 29, the latter gives out an impulse to station 39 via a connection 29', so as to cause the trans mission of the here determined final cutting length L to the shear control.

In order to control the rotating shear 28 from the computed cuttin. length L there is required a recalculation 5 of the cutting length L into the cutting time sequence T.

To that end there is formulated the quotient at a fourth station 45 of the computing apparatus from the computed cutting length L and the measured discharge speed v of the rolled bar from the last finishing roll stand, which quotient determines the through-travel time of the bar, respectively the cutting sequence time T.

The discharge speed v is determined from the rotational speed of the rolls as measured by the tachodynamo 30 at station 46, with consideration being given to an adjustable constant Av for the forward lead loss.

The cutting sequence time T is transmitted to an impulse generator 48 which influences the cuts of the rotating shear, which impulse generator adds for the first cut at the moment of signaling by means of the photo cell 29 to the cutting sequence time an adjustable time AT from the adjusting device 50 for compensating for the path of the forward end of the bar from the photo cell to the shear. Thus, from the moment of signalling by the photo cell 29, the station 48 gives a cutting impulse via conductor 49 to shear 28 only after expiration of a time T +AT. But since for the subsequent cuts the influence of the path from the photo cell to the shear is dropped, the added value AT is again extinguished at station 48 by an impulse by means of a return signalling conductor 51 after the first cut has been completed, so that thereafter cutting impulses are given in the tact of the time T. The exinguishing of AT can, for example, be accomplished in that under the influence of the return signalling via 51 the same value AT is again subtracted, just as it had previously been added. The extinguishing of the value AT continues until, after the rearward bar end has passed the photo cell 29, the impulse feed is interrupted, as, for example, by the retarded dropping of the photo cell current. Then with the next first cut, station 33 again delivers an impulse in the time T+AT after the signalling of the photo cell.

In FIGURE 1 there are shown the distances pertaining to the times T:L and AT. If the distance of the photo cell 29 from the shear 28, which corresponds to the time AT, is greater than the bar length L, respectively the cutting sequence time T, then the photo cell current must be maintained, even after passage of the bar end, for a time T, i.e. its cut-off must be delayed, as by means of a time relay, so the extinguishing of AT is maintained at station 48 and a final cutting impulse is still given, since the impulse generator 48 delivers impulses only during the existence of a photo current. A synchronization of the shear 28 with the rotational speed of the rolls of the last roll stand is secured by means of the conductor 52.

xample A billet of a finishing cross section Q=8O X 80 mm. and of a specific weight 785 kg/dm. is to be subdivided into equal lengths L without any cutting waste, with the tolerance condition AL=L L =10.2 m.9.5 m.=0.7 m.

be given. The constants for Q, 7, L and L as well as an estimated bar number p=10 are adusted on the devices 35, 36, 41, 42 and 38.

From the scale, a weight of the starting material, 6:5.300 kg. is determined.

In 33 the total bar length Q.'y 50 I is calculated. Q/y is with 50 kg./rn. the weight per unit of length of the billet bar.

In 37 the preliminary cutting length is computed with a p 1O LII t is assumed that the photo cell 29 is placed ahead of tie shear 28 by Lp=l3 m.

With a constant rotational speed of the rolls of v=2 rn./sec. the time constant for the path of the bar end from the photo cell to the shear becomes which has been previously calculated and adjusted at 50.

The first cut is carried out T+AT=483 +6.5: 1 1.35 sec.

later than when the forward end of the bar passes the photo cell 29; thereafter the cutting impulses follow in the tact of 4.83 see. by means of extinguishing AT.

At the last cut the rearward bar end has already passed the photo cell 29, since L is greater than L, namely, by 139.65=3.35 m. The corresponding time is At least during this time a maintenance of the signal voltage in the circuit from the photo cell to the impulse generator 48 must be assured by means of a time relay, so that the last out will still be triggered.

In FIGURE 3, L signifies the theoretical total bar length determined from the weighing operation, and AL the plus tolerance to be added. This and a minimum remainder length R should in summa at most be equal to the smallest individual length L which holds for all previous individual bars. FIGURE 1 reproduces now by means of the computing apparatus according to FIG- URE 2 a length L, plus AL which is fictitiously subdivided into equal individual lengths L which lie within the zone of length tolerance. Now, if the effective total length is equal to the sum L plus AL then the pre-determined tolerance was correct and all individual bars will be of the same length, without a remainder occurring.

But if, as according to FIGURE 3, line 0, the eifective total length L equals the theoretical L then the length AL is missing on the last bar. The remainder piece will be the same as, or greater than, R depending on whether the subdivision was based on a value of exactly L or on one above it but still under L If, as according to FIGURE 3, line a, the effective total length equals L AL.,, then there is missing the amount L2 times AL from the fictitious individual length of the last bar. With the i tolerances AL selected in the presentations for reasons of clearness rather large as compared with the minimum length R the remainder bar with the length R in FIGURE 3, line d, is too short. However, it could be long enough if the condition 2 X 0 min' min were fulfilled, but in which case nevertheless the theoretical L value is falsified additively only by IXAL The apparatus for carrying out the method described above, according to FIGURE 4, is expanded as against that of FIGURE 2 to the extent that for the adjustment of the plus-tolerance AL there is provided an adjusting device 55, the adjusted value of which is added to the AT =6.5 sec.

calculated total bar length in a device 55 ahead of the computing device 37. Now, in the computing device 37, in connection with the circuits 39, 40, 4d, 38, an

individual bar length L is calculated on the basis of the sum L plus AL Of course, the plus-tolerance can also be expressed as a percentage of the initial weight of the total length and can be adjusted as apercental tolerance on the devices 33, 34, 35, S6 or 32.

In order to keep the plus-tolerance L small and, correspondingly, the rrinimum length R as humans possible, the invention provides additional means for bringing the calculated total length L into the greatest possible agreement with the actual total length.

For this purpose, a measuring device 57 is placed beyond the last roll stand 27 for determining the emerging finished cross section of the rolled stock. A known device of this nature works with scanning rays. Its measured value is fed to the device 35 for pre-adjustment of the finish cross section Q, which device 35'is arranged in such a way that the pro-adjusted value'is replaced by the effective value Q ff as soon as such an elfective value is signalled. Since the computing apparatus operates continuously, the calculation is being repeated with-a corrected initial value, and thereby the resultL is corrected.

If it is determined that the tolerance addition AL is always missing on a remainder piece, then L and L are largely in agreement, wherefore the tolerance addition 'AL need no longer be adjusted at all.

It can happen, because of a changed value Q for the finished cross section, that for maintenance of the length tolerance, for the individual bars, AL=L -L the bar number p is changed at 33. From the time standpoint this might no longer be admissible if the shear 28 is placed very close to the last roll stand 27. In such cases it is desirable to feed the measured value of the measuring device 57 to a computing device 58 in which the quotient Q Qefi is formulated. This result is multiplied in the computing device 59 by the cutting sequence time T, so that the cross section ratio between theoretical and actual value influences the cutting sequence time T in the sense that thelatter becomes greater if the ratio is greater than 1, and vice versa.

But a corrected cutting sequence time T leads to the correct individual lengths Lcorresponding to it, and therebyto a remainder piece of a pre-determined minimum length, only if the speed of the rolled stock after its exit from the last roll stand corresponds to the value introduced into the computing process at iii). If the actual speed is greater, because of a forward increase in the roll gap, greater individual lengths L will also be obtained, even though nothing changes in the total length. These deviations in length. will finally show up in the remainder piece, so that the latter could easily be lacking in proper length.

To avert-this discrepancy, it is possible to determine the actual speed of the rolled stock ahead of the shear by means of scanning or by a photo cell arrangement on the rolled stock itself and to introduce itinto the calculation, instead of taking it off the rolls. Another way, according to the invention, consists in controlling the actually cut individual lengths L and in currently adjustlength L. The signal from the photo cell 60 is fed via the conductor 62 to the control for the shear and replaces the command of the cutting sequence time T which, as noted, might be too greatbecause of a possible forward increase. Thus, by means of the arrangement of photo cell 60, absolutely correct individual lengths L are being cut, independently of the actual speed of the rolled stock.

If the shear does not run continuously but must be actuated before-each cut, the accelerationis given consideration in that the photo cellis adjusted to asmaller distance than the individual lengthL from the shear. For this, there is provided an adjusting device 63 onwhich is adjusted a length L corresponding to the operating time of the shear at a medium speed of the rolled stock, which length is deducted in the computing device 64 from the individual length L obtained by computation.

The last described apparatus for cutting to the theoretical individual lengths L obtained by calculation can make superfluous the recalculation into cutting sequence time disclosed in connection with FIGURES l and 2 as well as the releasing of the command by the photo cell 29 with all of the computing operations being connected therewith. Thus, the devices 29 and 45 to 51, and therewith also the devices 58 and 59 according to FIGURES 3 and 4 can be omitted.

From the foregoing it will be apparent to those skilled in this art that I have provided a very efiicient, and relatively simple, method and apparatus for accomplishing the objects of the invention; and it is to be understood that I am not limited to the specific embodiments of the invention shown and described herein as various modifications may be made therein within the spirit of the invention and the scope of the appended claims.

I claim:

1. An apparatus for subdividing an elongated metal bar which is rolled from a single billet by passing the billet through the successive forming rolls of a mill train, into a plurality of substantially equal. length individual sections, said apparatus comprising: means for weighing said billet before rolling, shear means operative to cut said elongated bar into individual sections, shear control means for controlling the operation of said shear means in accordance with signal impulses received bysaid control means, an electronic calculating mechanism having a first station which is operative to calculate the total length of a bar of known cross-sectional configuration to be rolled from said billet by multiplying the Weight of said billet by the preadjustable reciprocal value of the weight per unit of length of said bar; a second station which is operative'to determine the length of said individual sections by dividing the total lengthof said bar of known cross-sectional configuration by the adjustable number of individual sections to be cut by said shear means; and a third station at which a cutting length tolerance obtained with pro-adjustable extreme values is compared with the determined-length of said sections for changing with an impulse the number of individual section cuts determined by said second station so long as the determined cutting length lies outside the adjustable extreme values.

2. An apparatus for subdividing an elongated metal bar as defined by claim 1, in which a photoelectric cell is disposed beyond the last forming roll of said mill train, said photoelectric cell being operative upon the passage of the forward end of said bar to initiate by means of an impulse the retransmission of the calculated cutting length to said shear control means.

3. An apparatus for subdividing an elongated metal bar as defined by claim 2, in which a measuring device which is operative .to determine the effective finished crosssection of said bar and which effective finished crosssect-ion replaces a pre-adjusted cross-section value, is disposed adjacent said photoelectric cell.

4. An apparatus for subdividing an elongated metal bar as efined by claim 1, in which said second station is also operative to add a falsifying tolerance to the calculated theoretical length of said bar for the purpose of determining the individual section length of the theoretical total bar length.

5. An apparatus for subdividing an elongated metal bar as defined by claim 1, in which are also provided: a measuiing device which is disposed beyond the last forming roll of said mill train and is operative to determine the efiective finished cross-section value and impart it to a computing device by which the quotient between the preadjusted cross-section value and the finished cross-section value is determined, and a second computing device by which the said quotient is multiplied by the cutting sequence time.

6. An apparatus for subdividing an elongated metal bar as defined by claim 1, in which said first station comprises a plurality of elements into one of which a calculated cross-sectional area is manually introduced, into another of which the specific weight of the rolled material is manually introduced and another of which elements determines the reciprocal values of a calculated area times the specific weight, another element receiving said reciprocal value and multiplying the same by the actual weight of the billet being rolled so as to determine the theoretical length of an elongated section rolled from said billet.

7. An apparatus for subdividing an elongated metal bar as defined by claim 6 in which said second station comprises a first element into which the theoretical number of sections into which said bar is to be divided is manually set, a second element in which the output of said first station is divided by the number manually set into the first element of said second station so as to determine the cutting length of said individual section.

8. An apparatus for subdividing an elongated metal bar as defined by claim 7 in which said third station comprises an element into which a theoretical minimum and a theoretical maximum length of said individual sections are manually set, said last-mentioned element being operative to compare the cutting length of said individual sec tion as determined by said second station with the theoretical minimum and maximum value manually set thereinto and to decrease the theoretical number manually set into the first element of said second station if the said cutting length is less than said minimum and to increase the said number if said cutting length is greater than said maximum and thereby effect a recalculation of said cutting length in the said second element of said second station.

9. An apparatus for subdividing an elongated metal bar as defined in claim 8 and further including a fourth station operative to determine the cutting sequence of said shear means by dividing the finally calculated cutting length of said individual sections by the measured rate of travel of said elongated bar between the last roll stand of said mill train and said shear means.

10. An apparatus for subdividing an elongated metal bar as defined in claim 9 in which the operation of said shear means is synchronized with the rate of travel of said elongated bar between said mill train and said shear means by a pair of tachodynamos, one of which is disposed adjacent the last roll stand and the other of which is disposed adjacent said shear means.

11. An apparatus for subdividing an elongated metal bar as defined by claim 10 in which the operation of said electronic calculating mechanism is initiated and maintained by a photoelectric cell which is disposed adjacent the last roll stand of said mill train.

References Cited by the Examiner UNITED STATES PATENTS 1,914,985 6/33 Thomas -562 2,958,243 11/60 Foster 80-3 3,066,562 12/62 Barnett et al. 83-74 WILLIAM J. STEPHENSON, Primary Examiner.

LEON PEAR, Examiner. 

1. AN APPARATUS FOR SUBDIVIDING AN ELONGATED METAL BAR WHICH IS ROLLED FROM A SINGLE BILLET BY PASSING THE BILLET THROUGH THE SUCCESSIVE FORMING ROLLS OF A MILL TRAIN, INTO A PLURALITY OF SUBSTANTIALLY EQUAL LENGTH INDIVIDUAL SECTIONS, SAID APPARATUS COMPRISING: MEANS FOR WEIGHING SAID BILLET BEFORE ROLLING, SHEAR MEANS OPERATIVE TO CUT SAID ELONGATED BAR INTO INDIVIDUAL SECTIONS, SHEAR CONTROL MEANS FOR CONTROLLING THE OPERATION OF SAID SHEAR MEANS IN ACCORDANCE WITH SIGNAL IMPULSES RECEIVED BY SAID CONTROL MEANS, AN ELECTRONIC CALCULATING MECHANISM HAVING A FIRST STATION WHICH IS OPERATIVE TO CALCULATE THE TOTAL LENGTH OF A BAR OF KNOWN CROSS-SECTIONAL CONFIGURATION TO BE ROLLED FROM SAID BILLET BY MULTIPLYING THE WEIGHT OF SAID BILLET BY THE PREADJUSTABLE RECIPROCAL VALUE OF THE WEIGHT PER UNIT OF LENGTH OF SAID BAR; A SECOND STATION WHICH IS OPERATIVE OF DETERMINE THE LENGTH OF SAID INDIVIDUAL SECTIONS BY DIVIDING TH TOTAL LENGTH OF SAID BAR OF KNOWN CROSS-SECTIONAL CONFIGURATION BY THE ADJUSTABLE NUMBER OF INDIVIDUAL SECTIONS TO BE CUT BY SAID SHEAR MEANS; AND A THIRD STATION TO BE CUT BY SAID SHEAR ANCE OBTAINED WITH PRE-ADJUSTABLE EXTREME VALUES IS COMPARED WITH THE DETERMINED LENGTH OF SAID SECTIONS FOR CHANGING WITH AN IMPULSE THE NUMBER OF INDIVIDUAL SECTION CUTS DETERMINED BY SAID SECOND STATION SO LONG AS THE DETERMINED CUTTING LENGTH LIES OUTSIDE THE ADJUSTABLE EXTREME VALUES.. 